Ornamental sheet metal structure and method of producing the same



D. E. HUNTER Feb. 13, 1934.

ORNAMENTAL SHEET METAL STRUCTURE AND METHOD OF PRODUCING THE SAME Filed Feb. 2. 1931 2 Sheets-Sheet 1 Feb. 13, 1934. D, E HUNTER 1,946,694

ORNAMENTAL SHEET METAL STRUCTURE AND METHOD OF PRODUCING THE SAME Filed Feb, 2, 1931 2 Sheets-Sheet 2 Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE ORNAMENTAL SHEET METAL STRUCTURE AND METHOD OF PRODUCING THE SAME Application February 2,

3 Claims.

This invention relates to improvements in ornamental sheet metal structures, and more particularly to methods of fabricating ornamental tubular metallic structural materials for use in the construction of such articles as metal furniture and fittings, and in the production of metallic exterior and interior trim for buildings.

The term, ornamental sheet metal structures, is therefore somewhat comprehensive in its scope, in that it includes two fields somewhat removed in an individual sense, though quite analogous, from the standpoint of the decorative arts. Taking for example a decorative column of sheet metal in tubular form, if produced in small sizes, would serve as the legs of a metal desk, table or chair, while the same column increased in size many fold would serve to encase the structural column of a building. In either use the column would represent an ornamental structural member, although in the first instance it would be a supporting member, and in the other it would be merely a casing applied over the rough surfaces of a supporting member. However, the method of forming and assembling the structural members would be generally the same, and hence the adaptability of the present invention to more than one class of ornamental and decorative sheet metal structures.

The use of sheet metal tubing, both plain and ornamental, has been used in the manufacture of metal furniture, but with the gradually increasing demand for the simple yet efiective designs found in wood furniture, their reproduction in metal, using old methods and materials, has been found to be too expensive to be commercially profitable.

Taking the column again as an example, it is quite practical to form a straight table or desk leg of round or square cross section from a length of metal tubing, but to produce, say, a fluted leg or one that tapers or is otherwise irregular in cross section, requires elaborate and expensive die pressing and drawing operations. Moreover, in using tubular stock it is quite difilcult to accurately notch or slot them for joining with other members or parts. The same holds true in other structural shapes, such as corner constructions, pilasters, beams, cornices, mouldings and other ornamental or decorative details found in metallic cabinet work as well as interior trim, and therefore the principal object of the invention is to provide an improved and commercially practical method for fabricating sheet metal for these uses.

The basis of the invention regardless of its pan- 1931. Serial No. 512,797

joint is formed, such as completely conceals the sectional construction of the member.

In disclosing the invention, several typical shapes and forms have been illustrated in the accompanying drawings, in which:

Figure l is a view in elevation of an ornamental column such as might be used for the leg of an article of metal furniture.

Figure 2 is a cross-sectional view of the column shown in Figure 1.

Figure 3 is a detail view of the two sections of the column prior to their assembly.

Figure 4 is a cross-sectional view of a circular fluted column of sectional construction.

Figure 5 is an enlarged detail view in cross section through one of the joints between overlapping edges of the sectional construction shown in Figures 2 and 3, the same also being applicable to any corner construction.

Figures 6, 7 and 8 are detail views similar to Figure 4, showing details of different corner constructions, and

Figures 9, l0 and 11 are details of diiferent styles of decorative trim or sectional surfacing covering.

Referring to Figures 1 to 3, inclusive, the memher 1 is a tubular column of sheet metal such as would be suitable for making the legs of a desk or table. As such the member is generally square in cross section and of uniform dimensions. In ornamentation it is relatively simple, the decorative features being confined to the corners, which are conventionally decorated by what may be termed a quarter-rounded moulding 2, with smaller rounded fillets 3, 3 along either side of the mould, giving the column a comparatively simple yet dignified appearance.

As produced by the present process or method, the member is made up of two longitudinal sections 1a, 1b which are stamped from sheet metal of the proper gauge in the form of flat blanks, and then placed in a press and shaped to the angular shapes shown in Figure 3. The two sections meet and are joined along diagonally disposed corners, both having complementary overlapping marginal portions 2a, 2b which conform to the contour of the rounded mould 2, and the fillet 3 between said mould and the body of the section. Thus when the two sections are joined together, the rounded marginal portions of one section overlap the complementary portions of the other section with their edges abutting against the shoulders just beyond the fillets 3, 3, as shown in greater detail in Figure 5.

Now, in order to obtain a tight joint at the overlapping corners, and to maintain the same profile or surface contour at all corners, the overlapping marginal portions of the two sections 1a and 1b are treated somewhat differently. Thus, referring to Figure 5, the section 1a having the inner or underlapping rounded marginal portions 2 is bent or shaped in the formation of the rounded mould, so that it is offset inwardly at a slightly greater depth than the complementary overlapping mould 2b of the other section 1b, this being evidenced by the increased depth of the shoulder at 4 connecting the body of the section with the rounded mould 2a. Moreover, at the base of the shoulder 4 there is provided a rounded depression or rabbet as at 5, which provides a clearance space along the edge of the overlapping rounded mould 2a, so that when the two sections are assembled, as shown in Figure 2, the edge of the overlapping mould 2b is drawn tightly down into abutting contact with the shoulder 4, thus making a joint, which is scarcely visible on the surface beyond the hair line that marks the seam of the joint. The two sections 1a and 1b are preferably joined by springing the overlapping edge portions together, the sections having sufficient resiliency so that they yield as the rounded edge moulds slide over each other, and finally snap together. The two sections thus joined become a fairly rigid structure under the tension exerted by the edges of the one gripping those of the other, and to this end the sections are originally shaped so that the angle included between the walls of the one (1a) having the underlapping edges is a shade over, and the other (11)) a shade under 90.

Thus in the joining of the sections together it will be noted that the outer seam or joint is quite tight with the edge of the outer mould 2b abutting against the shoulder 4 just above the depression 5 which forms in effect a clearance pocket, permitting the snug fit which results in a virtually invisible or concealed joint. Moreover, to accentuate the close contact of the overlapping sections, the edge of the outer mould 2b may be slightly beveled as at 20, and the corresponding marginal portion of the inner mould 2a is bent inwardly to a slight extent beyond the true arc, thereby leaving a slight clearance space between the surfaces as at 6.

Now, assuming the column thus assembled is to form a structural unit, such as a leg or other supporting member, the sections would preferably be welded together along the corner joints, either by the spot or seam process of electric welding as indicated at w, Figure 5.

On the other hand, considering the sectional tubular member as the ornamental exterior of a structural column, the two sections would merely be applied around the column and snapped together at their edges, the tension holding them together without welding and the joints concealed to give the appearance of a solid column.

It may be here observed that in the more modern treatment of public building interiors, sheet metal is extensively used over columns, beams, pilasters and other architectural details, to give the ornamental effect desired, as for instance, in burnished steel or bronze.

Figure 4 shows a column '7 of circular crosssection with a fluted surface detail, and which may be either straight or tapered. This column is made up of sections 7a and 7b which have overlapping edge portions which are treated in the same manner as described in connection with Figure 5.

In all cases, whether in metal furniture or interior trim, the sectional construction is not confined to tubular structures, since the same type of joint may be employed wherever two sections are joined, as for instance in any corner construction. Thus in Figures 6 to 8 are shown several different treatments of ornamental corner designs, and which illustrate the use of the same style of overlapping joint before described. By comparing these Figures 6, '7 and 8 with Figure 5, the common features will be seen without a detailed description.

Now, in Figures 9 to 11 is illustrated the application of the same novel features to ornamental sheets adapted to be applied over large areas, I

ures 10 and 11 show variations of the same type of structural materials.

The principal advantage of the method herein disclosed over the ordinary practice in forming tubular structural members or ornamental encasing sheets, is the development of a suitable joint which permits the use of flat sheet material in the production of sections which can be readily pressed to reproduce the desired ornamental eifect and then be assembled into a complete structure. The advantage of this process as applied to metal furniture is particularly noteworthy, as it makes it possible to reproduce a large variety of designs, impossible of accomplishment in tubular stock.

For example, in furniture construction, the

notching and piercing of the tubular members required for assembling different parts together, can be easily and accurately carried out in the cutting of the blanks from fiat stock, but is quite diificult and expensive in tubular stock.

Again, the type of joint herein disclosed, greatly facilitates the operation of assembling the sections of a column or other structural member, inasmuch as a permanent joining as by welding is not always required. Thus in applying a sheet metal casing for a column, the sections can be snapped together without revealing a break at the joint, and the section can later be removed if occasion should arise.

The process discloses a new and useful treatment and handling of sheet metal in the construction and assembly of ornamental tubular or encasing members, and as repeatedly observed, is applicable to different fields and arts of metal ware, therefore I do not wish to be limited in the scope of the invention herein set forth, except in so far as defined by the appended claims.

I claim as my invention:

1. A sheet metal tubular structure comprising a plurality of sheet metal sections having substantially the same sectional contour and com-' plementary marginal portions defined by a shoulder spaced inwardly from the edges thereof, said sections being joined by springing the margins of one section sufiiciently to overlap the margins of the other section, the shoulder of the underlying marginal portion being accentuated by narrow rabbets extending along the bases thereof and adapted to effect tight, substantially seamless joints between the sections.

2. An ornamental sheet metal tubular structure comprising a pair of sections having substantially the same cross-sectional contour and complementary overlapping marginal portions defined by shoulders spaced inwardly from the edges thereof, said sections being united by springing one sufiicently to bring its marginal portions into overlapping engagement with the marginal portions of the other, the shoulder of the underlying marginal portion being relatively deeper than the overlapping portions and having narrow rabbets along the base thereof whereby said sections are held together by the tension exerted by one upon the other, with the edges of the overlying marginal portions abutting edgewise against the shoulders of the underlying marginal portion to form a substantially invisible seamless joint.

3. An ornamental tubular sheet metal structure comprising a pair of complementary right angular sections of substantially the same cross sectional contour joined together along diagonally disposed corners, said joints being formed by complementary rounded marginal portions having shoulders along their inner edges and adapted to be tensionally locked together by springing the marginal portions of one section over those of the other section, whereby the free edges of the overlapping portions abut against the shoulders of the underlying portions, the latter having narrow concave rabbets extending along the same below the lines of abutting contact to effect substantially invisible seams at the joints.

DAVID E. HUNTER. 

